Never done it or heard of it, but considering the thickness of a sun visor and a Lilliput, I'd cut a Lilli hole right out of the visor leaving some extra covering material around the edges. Then wrap that extra material into the cutout and glue it. And install the Lilliput in the hole so the screen side is flush on the front, and the back side and vents are exposed in the back. These screens get hot and can't be sealed up. Dealing with the cables would be another trick.